This observational study evaluates how organizational and financial arrangements in Medicare managed care and fee-for-service (FFS) settings affect the use and content of primary and referral care. The proposed study adds a comprehensive analytic phase and valuable longitudinal and chart abstraction components to an already funded cross-sectional study. The specific aims of the overall investigation are: Specific Aim 1: To compare use of services relative to accepted clinical standards for persons with type 2 diabetes in Medicare managed care relative to FFS Medicare. Integral to this specific aim is distinguishing variation in case-mix from system performance differences. Specific Aim 2: To determine whether race, ethnicity, or socioeconomic status is independently associated with functional status, use of primary and referral care, and the quality of the process of care in managed care and FFS settings. Specific Aim 3: To evaluate Specific Aims 1 and 2 relative to within managed care arrangements, such as generalist- specialist risk-sharing arrangements. This study should deepen the understanding of the role of financial and organizational arrangements on access to and quality of care provided to Medicare beneficiaries with diabetes.